Truss-type cargo-carrying vehicle

ABSTRACT

A truss structure includes upper and lower beams with vertical interconnecting beams on which cargo of any type may be suspended. The truss structure is adapted to be supported on horizontally spaced wheel suspensions, such as is common in overthe-highway vehicles, or it may be disposed in and be connected to structural components in aircraft wherein the truss structure supports the cargo and provides a primary structural component of both modes of transportation. In a railway car a relatively narrow upright truss structure is supported at its opposite ends on trucks. The truss structure is provided at opposite ends with short sill sections which contain coupler housings supporting conventional couplers. At opposite ends of the truss structure horizontal stabilizing members extend laterally outwardly of the truss structure and are adapted to be connected to conventional single or double axle trucks in conventional fashion. The narrow truss structure is the sole structural support of the car and provides on opposite sides thereof, between the trucks, a free and unencumbered space to which ready access may be had by suitable powered handling devices which may lift cargo into position to be connected and suspended on opposite sides of said truss structure. A modified embodiment comprises a railway car which includes a pair of truss sections which have outer ends supported on single axle trucks, and adjacent inner ends supported on double axle trucks by means of an articulated connector assembly.

United States Patent [191 Bateson et al.

1 Apr. 23, 1974 TRUSS-TYPE CARGO-CARRYING VEHICLE [75] Inventors: Norman E. Bateson, Munster, Ind.;

William L. Pringle, Grosse Pointe Shores, Mich.

Related US. Application Data [62] Division of Ser. No. 65,461, Aug. 20, 1970, Pat. No.

[52] US. Cl. 296/1 A, 105/368 R [51] Int. Cl B60p 3/06 [58] Field of Search; 296/1 A, 3; 105/368 R; 280/80 B [56] References Cited UNITED STATES PATENTS 2,837,036 5/1958 Fraenkel 105/366 R 2,268,167 12/1941 Raine 280/80 B X 3,246,912 4/1966 Cunha... 280/80 B X 3,182,610 5/1965 Jones 105/368 R 2,605,113 7/1952 Gi1more..... 280/404 X FOREIGN PATENTS OR APPLICATIONS 383,264 12/1964 Switzerland 105/368 R 346,951 7/1922 Germany 105/368 R 405,950 7/1966 Switzerland 280/80 B Primary Examiner-David Schonberg Assistant Examiner-Leslie J. Paperner Attorney, Agent, or FirmRichard J. Myers [57] ABSTRACT A truss structure includes upper and lower beams with vertical interconnecting beams on which cargo of any type may be suspended. The truss structure is adapted to be supported on horizontally spaced wheel suspensions, such as is common in over-the-highway vehicles, or it may be disposed in and be connected to structural components in aircraft wherein the truss structure supports the cargo and provides a primary structural component of both modes of transportation.

In a railway car a relatively narrow upright truss structure is supported at its opposite ends on trucks. The truss structure is provided at opposite ends with short sill sections which contain coupler housings supporting conventional couplers. At opposite ends of the truss structure horizontal stabilizing members extend laterally outwardly of the truss structure and are adapted to be connected to conventional single or double axle trucks in conventional fashion. The narrow truss structure is the sole structural support of the car and provides on opposite sides thereof, between the trucks, a free and unencumbered space to which ready access may be had by suitable powered handling devices which may lift cargo into position to be connected and suspended on opposite sides of said truss structure.

A modified embodiment comprises a railway car which includes a pair of truss sections which have outer ends supported on single axle trucks, and adjacent inner ends supported on double axle trucks by means of an articulated connector assembly.

9 Claims, 14 DrawingFigures PATENTEDAPR 23 I974 SHEET 1 BF PATENTED APR 2 3 1974.

sum 3 OF 7 PATENTEDAPR 2 I91 3 806" 182 SHEET 5 [IF 7 Ph rmtmm lei-m SHEET 5 OF 7 TRUSS-TYPE CARGO-CARRYING VEHICLE This is a division of co-pending US. Pat. application, Ser. No. 65,461 filed Aug. 20, 1970, of Norman E. Bateson and William L. Pringle now US. Pat. No. 3,675,592.

SUMMARY The prime object of this invention is.to provide an improved cargo carrier of simplified design wherein the primary structural member is an upstanding central longitudinal truss-type frame structure which is supported at its opposite ends on the wheels of a vehicle eliminating the usual and conventional deck or floor which also forms a structural part of the vehicle.

Another object of the invention is to provide a cargo carrier which includes a relatively narrow truss-like structure on which cargo is suspended, the said truss structure providing the primary structural support of a vehicle, such as a truck, trailer, or aircraft, and including a horizontal structural member projecting laterally outwardly of said truss structure to stabilize the same vertically.

The present invention, which includes the upstanding central frame structure, also includes at opposite ends thereof horizontally extending stabilizing members provided with center plate arrangements adapted to cooperate with car truck bolster center plates or vehicle suspensions in conventional fashion.

A central supporting framework comprises generally lower and upper longitudinally extending beams interconnected by suitable framing in the form of a truss or lattice-type structure. A railway car embodying this framework includes stub center sills supported on the horizontal stabilizing members which also include coupler housing adapted to contain conventional railway couplers.

The absence of any other laterally extending framework between the trucks of a railway car, or highway vehicle running gear, on the upstanding central frame structure provides for greater facility in loading and unloading and permits the cargo which may consist of containers or vehicles, etc., to be directly attached to, and suspended from, the truss structure of the frame. The invention may be utilized with the conventional two-axle trucks of a railroad car or may be combined with single-axle trucks disposed at opposite ends of the car, with the car comprising two individual articulated sections. Further, the truss structure may be placed on highway running gear and provide the primary structural component thereof or may provide the primary backbone or beam member of an' aircraft fuselage or hull.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a railway car;

FIG. 2 is an end elevational view of the railway car shown in FIG. 1,

FIG. 3 is a side elevational view of a modified railway car;

FIG. 4 is an end elevational view of a railway car shown in FIG. 3;

FIG. 5 is a cross-sectional view taken along the line 5-5 of FIG. 1; v

FIG. 6 is a cross-sectional view taken along the line 6-6 of FIG. 3;

FIG. 7 is a cross-sectional view taken along the line 7--7 of FIG. 3;

FIG. 8 is a side elevational view of a highway trailer embodying the truss structure of the present invention;

FIG. 9 is a cross-sectional view taken along the line 9-9 of FIG. 8;

FIG. 10 is a cross-sectional view through an airplane fuselage;

FIG. 11 is a crosssectional view taken along the line l1-l1 of FIG. 10;

FIG. 12 is a side elevational view of another modified articulated trailer construction embodying the truss structure of the present invention; I

FIG. 13 is a plan view of a portion of the trailer construction disclosed in FIG. 12; and

FIG. 14 is a cross-sectional view taken along the line 14-14 of FIG. 13.

DETAILED DESCRIPTION Referring now particularly to FIGS. 1, 2, and 5, an improved railway car is generally designated by the reference character 10 which includes at opposite ends thereof conventional trucks 11. Trucks 11 are of the two-axle type with wheels designated at 12 on axles 14. Each truck 1 1 also includes a truck bolster 13 on which is carried a conventional center plate 15. As shown in FIG. 5, side or outer bearings or supports 16 are suitably provided on the bolster 13.

The railway car 10 comprises primarily an upstanding central longitudinally extending truss or framing structure designated at 17 which includes a plurality of vertically extending horizontally spaced frame members 18. The frame members 18 are suitable connected to a lower relatively narrow longitudinally extending beam 19 and the upper ends of the frame members 18 are suitably connected to a similar upper beam 20. An intermediate horizontal beam 21 is suitably connected to the frame members 18 and the structure is rigidified by means of diagonal truss members 23 and 24. The framing structure 17 also includes a depending structure comprising a longitudinal beam 22 disposed below the upper edges of the railway wheels 12 and is supported by means of depending frame members 25 suitably braced by diagonal truss members 26. As best shown in FIG. 2, the framing structure 17 being of a truss type is of relatively narrow configuration with no parts thereof extending laterally outwardly on opposite sides thereof. Thus a rigid central upstanding structure of great strength is provided which does not require any laterally extending members such as cross-bearers, platform or deck, required in the conventional railroad car.

The longitudinal lower beam 19 of the truss structure 17 is connected at opposite ends thereof to short or stub length center sills 27 which are provided at their outer ends with open end coupler housing 28 adapted to contain conventional railroad couplers 29. As best shown in FIG. 5, each stub center sill 27 is provided with vertical side plates 30 connected to a top plate 31 and a bottom plate 32. As best shown in FIGS. 1 and 5, the rear end of each sill 27 is suitably recessed as indicated at 33 and has rigidly secured thereto a transverse stabilizing member 34 which may comprise one or more structural plates or elements and which in- -cludes a suitable center plate 35 adapted to cooperate with a' center plate l5 on the boltster 13 in conventional fashion. A conventional pin 36 projects from the stabilizing member 34 in conventional fashion through the center plates and 35. Each of the stabilizing members 34 also includes horizontally spaced bearing elements 37 adapted to cooperate with the side bearing 16 in conventional fashion.

The truss or framing structure 17 provides the sole support for cargo to be supported and suspended on the railway car 10. As schematically shown in FIG. 2, such cargo may consist of containers 38 carried on opposite sides of the truss structure 17 by suitable connecting bands or elements 39 which securethe containers directly to the framing members of the truss structure 17. It is contemplated of course that the cargo can be of any type and the structure 17 is particularly adaptable for supporting vehicles which would merely be suspended from the sides of the framing structure by well-know tie-down or securing means. Any cargo which can readily be suspended may be carried by the railway car described.

Thus it can be seen that a greatly simplified truss structure forms the sole structural beam for carrying cargo which may be suspended on the said structure. Additional strength is obtained by the utilization of the depending longitudinal beam 22 and its associate framing truss members. The relatively narrow design permits a maximum width dimension of cargo to be suspended thereon which still is within the lateral limits specified by the A.A.R. Further, a deck structure having the usual structural capabilities is unnecessary and undesirable. With the present type of narrow frame structure, loading is greatly facilitated since loading devices may be moved substantially right up against the truss structure without interference. Crane loading is particularly facilitated. Further, the structural transverse stabilizing members 34 are of sufficient magnitude 'and strength to provide for the vertical stability required.

DETAILED DESCRIPTION OF A MODIFIED I EMBODIMENT with slots 68 within which springs 69 are suitably secured. The axles 52, including conventional bearing portions, are vertically movable in the slots 68 and are cushioned therein by means of the springs 69 in a manner which is well known in the art.

Each 'of the truss or framing structure sections 58 includes vertical end frame members70 which are suitably secured to the lower beam 59 and are suitably connected to the upper beam 60. Intermediate vertical fraine members 71 are also similarly connected and are further connected to horizontally extending frame members 72 thus providing a suitable rigid type truss structure. The vertical frame members 70 also are connected at their lower ends, at the center portion of the car 50, to vertical webs 73 and 73 as shown in FIG. 3. The web 73 is provided with vertically spaced horizontally extending yoke members 74 which support a vertical pivot pin 75, as best shown in FIG. 6. The vertical web 73' of the adjacent sections 58 is provided with horizontally spaced vertically extending yoke elements 76 which are provided with aligned bores 77 through which the pin 75- extends. A horizontal pivot pin 78 is supported on the yoke element 76 and extends through a bore 78 provided in the pivot pin 75.

As best shown in FIG. 6, the relationship of the yokes 74 and 76 and their associated pivot pins is such that full articulation of the sections 58 is provided. Such articulation is conventional in the art and further need not be detailed for the present invention.

The web 73 also has connected thereto in the area of the lower yoke element 74, a transverse stabilizing member 79 as best shown in FIG. 6. The stabilizing member 79 includes a suitable downwardly extending center plate 80 adapted to conventionally cooperate with the center plate 56 supported on the bolster 55 and for this purpose a suitable pivot pin 81 is provided. The stabilizing member 79 also is provided at its lower surface with bearing pads 82 adapted to cooperate with the outer bearings 57. The features of the modification are thesame as those enumerated with respect to the first embodiment disclosed hereinabove. In both cars the car is identical'at opposite ends thereof. Each truck 51 comprises a single axle 52 being supported on conventional wheels. The car also is of articulated design and is provided centrally with a double axle truck 53 including axles 54 which support, as best shown in FIG. 6, a truck bolster 55 having a conventional center plate 56 supported thereon. The truck 53 also includes outer or side bearings 57 of conventional design which are carried by the bolster 55. The articulated car 50 comprises two sections of truss or framing structures 58 each of which includes a lower longitudinal beam 59 and an upper beam 60. Each lower beam 59 is provided at its longitudinally outermost ends with a diagonal beam portion 61. The diagonal beam portions 61 provided at the outermost opposite ends of the sections 58 are connected to horizontally extending stabilizing members 62 which have supported thereon stub center sills 63. As best shown in FIG.; 7, the stub center sills 63 include side plates 64 connected to a top plate 65 and a bottom plate 66. The stabilizing members 62 are of heavy structural fabrication and are provided with conventional depending pedestals 67 suitably provided the structure of the upstanding longitudinally extending truss performs the same function and has the advantages which are indicated. The invention thus can be utilized in a single-section railway car as indicated in FIG. 1 or two or more articulations may be provided, a two-section car being disclosed in FIGS. 3, 4, 6 and 7.

DETAILED DESCRIPTION OF ANOTHER MODIFIED EMBODIMENT In FIG. 8, another modified application of the truss structure invention is provided. In this case a highway trailer is generally designated by the reference character which is pulled by a conventional tractor 91 including a body 92 supported on ground wheels 93.

The tractor 91 has supported on the said body 92 a respectively connected by vertical end beams 102 and 103. The trailer 90 is supported on a conventional type of wheel suspension generally designated at 104 and includes suitable wheels 105 connected to the wheel suspension 104 by conventional spring devices. The wheel suspension 104 also includes a pair of horizontally extending frame members 106 which are connected to two vertically extending plates 107 by means of transverse beam members 108 connected to the frame members 106 at longitudinally spaced locations to provide a rigid construction. As best shown in FIG. 9, the vertical plates 107 are provided with openings 109 within which pins 110 are secured which suitably support a pair of track members 111 provided with a plurality of longitudinally spaced transversely aligned holes 112. The track members 111 are connected to the lower beam 98 and serve to secure the truss structure 97 on the wheel suspension 104. The wheel suspension 104 may be adjusted longitudinally on the track members 111 in conventional fashion by the removal and reinsertion of the pins 1 10. The longitudinal adjustment of the suspension is provided by means of the holes 112 which are placed in alignment with the holes 109 so that the pins 1 may be connected therethrough.

DETAILED DESCRIPTION OF ANOTHER MODIFICATION Referring now particularly to FIGS. 10 and 11, a cross-section through a portion of an airplane fuselage or hull, which is designated at 120, is disclosed. The fusilage or hull 120 has provided therein a truss structure 121 of similar construction as previously described. The truss structure 121 comprises an upper beam 122 and a lower beam 123 suitably interconnected by vertical beams 124. The truss structure 121 is also provided with a plurality of horizontal intermediate beams 125 in turn suitably connected to the vertical beams 124. The truss structure 121 provides the main support for the fuselage 120 and a skin or envelope 126 is supported on the truss structure 121 by suitable stringers or transversely extending brackets or gussets 131 suitably connected to the beams 122 and 123. The skin or envelope 126 may also be provided with suitable openings 127 which may be closed by means of doors (not shown). A suitable wing structure 128 is shown schematically and same is rigidly attached to the truss structure 121 ina manner which may be wellknown to anyone skilled in the art. Further, a suitable empennage or tail assembly is connected to the truss structure 121.

The truss structure 121 provides the primary structural support for the airplane fuselage 120, and vehicles 129, such as automobiles, are connected directly thereto and suspened therefrom by means of brackets generally indicated at 130. A conventional retractable landing gear structure 132 is suitably connected to the wing structure 128 as indicated in FIG. 11.

Referring now to FIGS. 12, 13 and 14, another modified trailer arrangement is disclosed which embodies the truss structure concept of the present invention. A conventional tractor 135 is schematically disclosed and includes a fifth wheel plate 136. A pair of trailers are disclosed and are designated at 137, each including a truss structure generally designated at 138. The truss structures 138 of each trailer 137 include an upper longitudinal beam 139 and a lower longitudinal beam 140 connected at opposite ends by vertical end beam members 141. A central vertical beam 142 also connects the beams 140 and 141. A stabilizing member or tongue 143 is provided at the front of each trailer and includes a kingpin 144 which in the case of the lead trailer is connected to the fifth wheel plate 136 in conventional fashion. The truss structure 138, and particularly the lower longitudinal beam 140, are connected to a rear stabilizing member 145 supported on a suitable wheel and axle suspension 146. A U-shaped guard 147 is positioned on opposite sides of the truss structure 138 to protect the cargo carried thereon. Side rails 148 connected to the U-shaped guards 147 are also provided for this purpose. The trailers 137 are shown carrying vehicles 149 which are suitable connected by means of brackets 150, in the case of the lowermost vehicles 149, to the central beam 142. In the case of the upper vehicles 149, the brackets 150, as shown in FIG. 14, connect the vehicles to the upper beam 139. Similarly, brackets may connect the upper vehicles 149 to the vertical end beams141. The brackets may be.conventional securing brackets which removably secure the underframe of a conventional automobile to the truss structure.

FIGS. 12 and 13 also show a dolly construction having a body 152 provided with a conventional landing gear 153. The body 152 also supports a conventional fifth wheel plate 154 and said body is supported by a suitable axis and wheel suspension 155. The stabilizing member 145 includes a pivot bracket 156, in turn connected to a pivot bracket 157 by means of a removable pivot pin 158. As shown in FIG. 12, the rearmost trailer 137 may have its kingpin 144 in engagement in conventional fashion with the fifth wheel plate 154 so as to provide for a train of two or more trailers. In the present modification, the truss structures again are the primary structural components of the trailer and also provide the primary means of suspension of the cargo.

In the various embodiments shown, the truss structures provide the primary or basic structural member of the vehicle and is also the primary member providing support for the cargo which is to be carried thereon. In the railway adaptation the truss structure is provided at its lower ends with the horizontal members which in turn are carried by the trucks of the railway car and provide vertical stability. In the highway trailer modification shown in FIG. 8, the truss structure is supported at its front by means of the fifth wheel plate which thus provides the horizontal or transverse stabilizing means for the truss structure 97. Likewise, the rear of the truss structure 97 is provided with transverse stabilizing means in the form of the vertical plates 107 which are adjustably and releasably connected to the lower beams 98.

In the aircraft construction shown in FIG. 11, the truss structure supports the skin or fuselage and also, the wings and empennage which are connected to the truss structure provide the vertical stability for the aircraft. Thus the truss structure in each instance is provided to act as a main structural member and also to carry the cargo directly suspended there'on.

In the embodiment shown in FIG. 8, the truss structure is disclosed as being removable relative to the fifth wheel plate 94 and the suspension 104 so that the truss including the cargo can be removed from the vehicles and therefore the vehicles can be attached to the truss structure either within or outside the factory in which the vehicles are manufactured wherein the truss structure can then be suitably handled and releasably attached to the wheel structure disclosed.

In the railway adaptation the truss structures also can easily be removed from the wheel trucks by merely raising the trussstructures from the trucks. In conventional railway car manufacture, the cars are lowered onto the bolsters of the trucks and may be likewise removed by merely lifting the cars from the said bolster structures of the trucks. Thus, in each of the instances disclosed in FIGS. 1 through 8, the truss structures are removable. Similarly, in the aircraft structure FIG. 11, the truss structure can be made removable relative to the aircraft wing and tail or empennage assembly but when attached thereto, provides the main structural support.

What is claimed is:

1. A highway trailer comprising:

a vertically extending supporting frame having a pair of sides defining a relatively narrow width and constituting the primary structural unit of the trailer,

said frame having substantially upper and lower vertically spaced longitudinally and horizontally extending beam members, fore and after longitudinally spaced vertically extending beam members including end beam members interconnecting with the horizontally extending beam members, and an intermediate horizontal beam member between said upper and lower horizontally extending beam members and extending between said vertically extending end beam members,

stabilizing means connected to said frame and projecting laterally outwardly with respect to said beam members,

movable means connected to and supporting said frame on the ground,

means connecting said stabilizing means to said movable means,

bracket means on said intermediate horizontal beam member adapted to suspend cargo on the vertical sides of said frame, and

said movable means including a trailer bogie suspennal laterally spaced members supported on ground wheels,

said stabilizing means including a laterally extending support structure connected to said longitudinal laterally spaced members, and

a connector bracket removably and adjustably connecting said frame to said support structure.

5. The invention in accordance with claim 1,

said trailer including a kingpin on said frame adapted to be connected to the fifth wheel of a highway tractor.

6. The invention in accordance with claim 1,

including a highway tractor having a fifth wheel structure removably connected to the frame of said trailer,

said fifth wheel structure and tractor providing a portion of said stabilizing means.-

7. A highway trailer comprising:

a vertically extending support frame having a pair of sides defining a relatively narrow width and constituting the primary structural unit of the trailer,

said frame having substantially upper and lower vertically spaced longitudinally and horizontally extending beam members and fore and after longitudinally spaced vertically extending beam members including end beam members interconnecting with the horizontally extending beam members,

a fifth wheel connector supported on one end of said frame and being connectible with a fifth wheel plate of a tractor, 1

a horizontal stabilizing member disposed at the other end of said frame,

a wheeled suspension supporting said frame,

bracket means on said frame adapted to suspended cargo on the vertical sides thereof, and

a pair of substantially U-shaped guards disposed on either side of said frame and extending below said lower horizontally extending beam member for at least partially encompassing and protecting cargo suspended on said frame.

8. The invention in accordance with claim 7,

said cargo being vehicles,and

said bracket means supporting said vehicles with their longitudinal axes parallel to the longitudinal axis of said frame and the sides of said vehicles being substantially parallel to the ground.

9. The invention in accordance with claim 7,

including a wheeled dolly disposed adjacent said wheel suspension and pivotallyconnected thereto for pivotal movement about a vertical axis,-and

a fifth wheel plate on said wheeled dolly adapted to connect to a second vehicle positioned in tandem relation. 

1. A highway trailer comprising: a vertically extending supporting frame having a pair of sides defining a relatively narrow width and constituting the primary structural unit of the trailer, said frame having substantially upper and lower vertically spaced longitudinally and horizontally extending beam members, fore and after longitudinally spaced vertically extending beam members including end beam members interconnecting with the horizontally extending beam members, and an intermediate horizontal beam member between said upper and lower horizontally extending beam members and extending between said vertically extending end beam members, stabilizing means connected to said frame and projecting laterally outwardly with respect to said beam members, movable means connected to and supporting said frame on the ground, means connecting said stabilizing means to said movable meanS, bracket means on said intermediate horizontal beam member adapted to suspend cargo on the vertical sides of said frame, and said movable means including a trailer bogie suspension.
 2. The invention in accordance with claim 1, said frame including a connector bracket removably connecting said frame to said bogie suspension.
 3. The invention in accordance with claim 2, said stabilizing means comprising laterally extending members connected to said connector bracket.
 4. The invention in accordance with claim 1, said bogie suspension comprising a pair of longitudinal laterally spaced members supported on ground wheels, said stabilizing means including a laterally extending support structure connected to said longitudinal laterally spaced members, and a connector bracket removably and adjustably connecting said frame to said support structure.
 5. The invention in accordance with claim 1, said trailer including a kingpin on said frame adapted to be connected to the fifth wheel of a highway tractor.
 6. The invention in accordance with claim 1, including a highway tractor having a fifth wheel structure removably connected to the frame of said trailer, said fifth wheel structure and tractor providing a portion of said stabilizing means.
 7. A highway trailer comprising: a vertically extending support frame having a pair of sides defining a relatively narrow width and constituting the primary structural unit of the trailer, said frame having substantially upper and lower vertically spaced longitudinally and horizontally extending beam members and fore and after longitudinally spaced vertically extending beam members including end beam members interconnecting with the horizontally extending beam members, a fifth wheel connector supported on one end of said frame and being connectible with a fifth wheel plate of a tractor, a horizontal stabilizing member disposed at the other end of said frame, a wheeled suspension supporting said frame, bracket means on said frame adapted to suspended cargo on the vertical sides thereof, and a pair of substantially U-shaped guards disposed on either side of said frame and extending below said lower horizontally extending beam member for at least partially encompassing and protecting cargo suspended on said frame.
 8. The invention in accordance with claim 7, said cargo being vehicles, and said bracket means supporting said vehicles with their longitudinal axes parallel to the longitudinal axis of said frame and the sides of said vehicles being substantially parallel to the ground.
 9. The invention in accordance with claim 7, including a wheeled dolly disposed adjacent said wheel suspension and pivotally connected thereto for pivotal movement about a vertical axis, and a fifth wheel plate on said wheeled dolly adapted to connect to a second vehicle positioned in tandem relation. 